Identification of the Male-Produced Aggregation Pheromone of the Four-Spotted Coconut Weevil, Diocalandra frumenti.

Abstract

The four-spotted coconut weevil, Diocalandra frumenti Fabricius (Coleoptera: Dryophthoridae), is a small weevil found attacking economically important palm species, such as coconut, date, oil, and Canary palms. Given the scarcity of detection and management tools for this pest, the availability of a pheromone to be included in trapping protocols would be a crucial advantage. Previous laboratory experiments showed evidence for aggregation behavior; thus, our main goal was to identify the aggregation pheromone in this species. The volatile profile of D. frumenti individuals was studied by aeration and collection of effluvia in Porapak-Q and also by solid phase microextraction (SPME) techniques. Moreover, solvent extraction of previously frozen crushed individuals was also performed. All resulting extracts and SPME fibers were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The comparison of male and female samples provided the candidate compound, 5-ethyl-2,4-dimethyl-6,8-dioxabicyclo[3.2.1]octane (multistriatin), whose biological activity was evaluated in olfactometer and field assays.